[PATCH] D64645: DAG: Handle dbg_value for arguments split into multiple subregs

[Jeremy Morse via Phabricator via llvm-commits]

jmorse added a comment.

Hmm, it looks like the extra DBG_VALUEs dropped in the msp430 test were legitimate locations for "b" -- if getUnderlyingArgRegs now fails but generates multiple {0,0} entries, the `ArgRegsAndSizes.size() > 1` block on line 5487 generates no (well, zero sized) locations and returns true. Wheras before EmitFuncArgumentDbgValue returned false, and another code path found a location for "b".

IMO it's probably fine to just not handle (i.e. return false) cases where there's no ValueMap record and only partial information from getUnderlyingArgRegs -- it's almost certainly a rare circumstance, isn't necessary for your use cases, all we need to do is not risk generating _wrong_ locations.


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  https://reviews.llvm.org/D64645/new/

https://reviews.llvm.org/D64645